International Business Machines Corporation

Sakae Uno

Koji Koyamada

Akio Doi

Tatsuo Miyazawa

Shinichi Iwai

A rendering method is provided that can materialize rendering processing from volume data at high speed using a surface rendering processor without restrictions on the structure of volume data to be processed. In the method, the sampling points of volume data V over a 3-D region are, in principle, arranged on the surfaces Q.sub.1, Q.sub.2, . . . Q.sub.n in equal intervals along a viewing ray L around viewing point p, and these surfaces are extracted as a set of triangles T.sub.i. Then, the volume data at each vertex of these triangles and the gradient vectors of this data are obtained by interpolation and generated as a triangle data group. High-speed volume rendering is materialized by displaying the data groups of these partially transparent triangles using a surface rendering processor. Since existing programs can be used for generation and processing of triangle data groups, there are no restrictions on the structure of the volume data to be handled.

Method and device for volume rendering using concentric spherical

To provide high-speed volume rendering without computing the points at which a viewing ray intersects with the boundaries of a volume data area. Visualizing a volume entails: selecting the exterior faces that face toward a viewing point from among a plurality of exterior faces of a volume data area, sorting the ones thus selected according to distance from the viewing point, selecting those exterior faces in the sorting order, and determining pixels on a projection plane corresponding to the exterior faces in question by scan conversion; computing pixel values along each viewing ray passing through each pixel for each corresponding exterior face until a final exterior face is encountered; such a final exterior face can be judged from information on many partial solids restricting the volume data area; when a viewing ray enters the volume data area again, pixel values to be added later on another exterior face are computed and added to the previous pixel values; the completion of processing of all exterior faces facing toward a viewing point is tantamount to the completion of processing all viewing rays.

Data visualizer utilizing exterior selected and depth sorted polyhedron

A digital display system includes a frame buffer store containing picture element data which is read out to address a color lookup table from which color data is read to a display device. The color lookup table comprises a first area storing color data common to a plurality of images and further areas each storing color data related to a corresponding one of the images. Data in the first area is generated by uniformly sampling a color space, data in the further areas is generated by sampling and quantizing input image data.

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Hachioji, Japan

Sakae Uno